Here, we seek to combine smartphone, wearable device and near-field communication technologies in a novel, integrated, unobtrusive system to improve individual adherence to anti-retroviral therapy (ART) and Pre- exposure prophylaxis (PrEP) for the treatment and prevention, respectively, of HIV infection. HIV treatment and PrEP require high levels of medication adherence sustained over many years to achieve optimal outcomes. Research on interventions to improve medication adherence, to date, has produced at best modest improvements with expensive interventions that are not sustainable outside of the research setting. The need for affordable, sustainable treatments is not confined to HIV care; it has been estimated that adherence to medications for chronic diseases averages about 50% in the developed world, while 80% or better is needed to obtain most of the benefits - and 95% or better for ART. If successful, this approach can be used to improve the management and outcomes of many chronic health conditions, such as heart disease, asthma, diabetes and cancer. This system, referred to as USE-MI (Unobtrusive Sensing of Medication Intake), builds upon the broad social acceptance of wearable electronic devices used by millions of Americans to establish individual health goals and provide real-time monitoring and feedback of individual performance. In this project, patients undergoing ART and PrEP will utilize the USE-MI platform to: Provide unobtrusive reminders to patients by using the combination of smartphone and wearable device alarms, the system will flexibly provide discreet medication reminders without drawing undo attention to the individual or the action. Unobtrusively detect medication intake - motion sensing and near-field communication technology will allow real-time confirmation of taking medications and provision of alerts in the event of medication error(s) due to the wrong drug or the wrong timing, without requiring any special action by the patient. Provide patient feedback - the smartphone application will give patients direct reports of their medication adherence and enable delivery of targeted behavioral interventions to enhance adherence. Improve communication between patients and care teams by offering clinicians and patients shared access to a medication scheduling application utilizing a mobile device platform to unambiguously establish medication regimen and to make immediate changes to the regimen as needed. Enhance and monitor medication adherence - a simple dashboard function will be made available to the patient and the treatment team to enable discussions about adherence, side-effect minimization strategies, and improvements and adjustments to medication regimens based on accurate data.